Year: 1971
Type: article
Abstract: Unit-cell parameters for the stoichiometric composition Bi 2 SeTe 2 have been determined accurately, using the least-square method, for reflections in the range of Bragg angles of 62-85°. A study of the thermal expansion of the layer-structure unit cell, determined over the temperature range 30-525°C, has revealed the anisotropy between the axial expansion coefficients, that for the c axis (16·2 × 10 −6 °C −1 ) being about 1½ times that for the a axis (10·2 × 10 −6 °C −1 ) at 50°C. The anisotropy almost disappears in the temperature range 400-475°C but the coefficients of expansion become unequal again, that along the a axis being greater at higher temperatures. Anomalous behaviour of the expansion coefficients, similar to that of Bi 2 Te 3 , has not been observed for this composition.
Authors: K D Kundra, S Z Ali
Institution: CSIR National Physical Laboratory of India
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
Funder: National Physical Laboratory
OpenAlex ID: W1997746393